The radical sense of the Hebrew word seems to be "habitable places," as opposed to water, and in this sense it occurs in (Isaiah 42:15) Hence it means secondarily any maritime district, whether belonging to a continent or to an island; thus it is used of the shore of the Mediterranean, (Isaiah 20:6; 23:2,6) and of the coasts of Elishah, (Ezekiel 27:7) i.e. of Greece and Asia Minor.
Smith’s Bible Dictionary
Isle
Smith’s Bible Dictionary, William Smith (1863). Public domain, from the CrossWire SWORD module.